Risk factors for HIV infection among adolescents and the youth: a systematic review

Abstract Objective: to identify and analyze HIV infection risk factors among adolescents and the youth. Method: this is a systematic review whose guide question is: what are the risk factors for HIV infection among adolescents and the youth?” In total, five databases and Google Scholar were searched in December 2021 and the found publications between 2012-2022 were filtered without language restriction. Studies were selected by two independent reviewers. The included materials were subjected to methodological quality evaluation and narrative synthesis. Results: overall, we included seven studies out of the 26,191 retrieved. All studies were conducted in Africa. We found that the female gender, older age, low schooling, Black ethnicity, multiple sexual partners, inconsistent use of condoms, alcohol consumption, and early sexual onset constituted risk factors for HIV infection in adolescents and the youth. Conclusion: understanding risk factors underscores the provision of health policies and intervention strategies to strengthen the responsiveness of health services and nursing teams’ care to reduce HIV transmission among adolescents and the youth.


Introduction
HIV infection is still considered a health challenge since estimates show 1.5 million new cases, 10.2 million untreated ones (out of 37.7 million), and 680,000 deaths related to acquired immunodeficiency syndrome in 2020 worldwide (AIDS) (1) .
According to global data, 5 Some factors, such as the unsatisfactory structure of health services and restrictions to its access, contribute to failures in behavioral and biomedical approaches to the adolescents and the youth, reflecting higher infection rates (1) . Moreover, biological, physical, mental, and social factors occurring during their transition to adulthood can also explain this vulnerability (3)(4) .
Due to these difficulties, nursing plays an important role in healthcare, strategically contributing to control the HIV epidemic among adolescents and the youth by recognizing and understanding how this population socially represents their vulnerabilities and infection risk factors, such as the non-use of condoms, women's difficulties of taking them with them, issues related to sexual pleasure for male adolescents, alcohol and/or drug use, multiple partners, difficulties in accessing services and sex education in schools, and incipient dialogue with parents and/or family members (5) .
Thus, nursing professionals, together with multidisciplinary teams, should prioritize public policies focused on psycho-emotional and social dimensions and intervene in environments in which these representations circulate since they may enable the interference in the reality of adolescents (5) . Some strategies, when incorporated into the preventive practices nursing performs in communities and appropriate to the needs and risk profile of this population, can positively impact public health and thus reduce HIV transmission and prevalence (6)(7) .
Considering that knowledge of the adolescents and the youth's vulnerability to human immunodeficiency virus infection can help identify failures in healthcare services, research have tried to understand the elements which are consistent with this phenomenon and guide the design of intervention strategies to ensure that health and nursing teams prevent the transmission of the virus. Thus, this study aimed to identify and analyze the risk factors for HIV infection among adolescents and the youth.

Method Study design
This is a systematic review based on the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) (8) and the stages of the "methodological guideline: how to conduct a systematic review and meta-analysis of observational comparative studies of risk factors and prognosis" recommended by the Brazilian Ministry of Health (9) . The protocol of this research was registered on PROSPERO (CRD42021276566) and published in the Research, Society and Development journal (10) .
A systematic review was chosen since it enables us to gather data, evaluate them individually, and publish the evidence found on a given area of interest to collaborate with decision-making and build knowledge on a given question (11) . For this, a research question was defined; eligibility criteria were chosen to screen primary studies; databases were selected; eligible studies were sought; retrieved articles were screened by reading their titles and abstracts; studies selected in the previous stage were fully read; study eligibility was assessed; data were extracted; the methodological quality of the included studies was evaluated, and their results were synthesized (9) .

Definition of the research question
To elaborate our guiding question: what are the risk factors for HIV infection among adolescents and the youth?", the acronym PECO (9)

Eligibility criteria
Primary studies that tested the hypothesis of the existence of some risk factor for HIV infection among adolescents and the youth were included. Adolescents and the youth were considered individuals aged between 15 and 24 years (12-13) . Thus, studies whose population included adolescents and the youth who were assessed Bossonario PA, Ferreira MRL, Andrade RLP, Sousa KDL, Bonfim RO, Saita NM, et al. together with people in the other age groups (0 to 14 years and 25 years or more) were excluded. Moreover, we sought to include observational-analytical studies, regardless of the country in which they were conducted. Search strategies were adapted to each database with the use of Boolean operators OR and AND (9) , as shown in Figure 1. In our search, no language limits were used but filters were applied: publication from 2012 to 2022 in all databases and Google Scholar and type of publication (article, conference article, review, systematic review, meta-analysis), except in LILACS and Google Scholar.

Scopus
(TITLE-ABS-KEY ("Young adult*" OR "The youth" OR "Young person*" OR "Young men" OR "Young women" OR "Young population" OR youngster* OR "Prime adult*" OR youth* OR adolescent* OR adolescence OR teenager* OR teenage OR teen*) AND TITLE-ABS-KEY (hiv OR "Human immunodeficiency virus" OR "Human immuno deficiency virus" OR "Acquired Immune Deficiency Syndrome virus" OR "Acquired Immunodeficiency Syndrome virus" OR "AIDS virus") AND TITLE-ABS-KEY ("Risk Factor*" OR "Predictive Factor*" OR predictor* OR "Associated factor*"))

Database Controlled/free vocabulary
Google Scholar* "the youth" "risk factor for HIV" "the youth" "risk factors for HIV" *For this platform, two search strategies were used to survey publications belonging to the grey literature as recommended by the Joanna Briggs Institute (15) , which enabled us to identify the number of items addressed in the selected studies according to the number of items predicted by the instruments. Finally, the results of the included articles were subjected to a narrative synthesis.
The methodological quality of each publication was analyzed so we could identify their main limitations.
In total, two articles contemplated all the items considered for an excellent methodological quality and five failed to achieve such excellence. Moreover, finding and controlling for confounding factors were the elements less addressed in these studies ( Figure 4).

Article screening
The references and abstracts found via database searches were exported to the QCRI Rayyan online systematic review application of the Qatar Computing Research Institute (14) . Then, duplicate publications were excluded before titles and abstracts were read by two independent reviewers. In cases of doubt or disagreement regarding their inclusion, a third reviewer was consulted. To confirm the inclusion of the selected studies, all eligible articles were fully read.
The search process and the eligibility of the materials found and included was shown in a flow diagram, as recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 Statement (PRISMA) (8) .

Data extraction
Data were extracted by a pair of reviewers and checked by a third one. For this, a standardized form was used, elaborated according to items suggested by the Joanna Briggs Institute for the extraction of data from systematic reviews of etiology and risk (15) : authors, year of publication, publishing journal, objective, type and setting, population and sample characteristics, recruitment procedures, follow-up or duration, exposure factors (independent variables), dependent variables, data analysis, adjustment for confounding factors, results, and comments. Note that no contact was made with the authors of the articles included to request missing or additional data on any stages of the studies.

Discussion
All studies included in this review were conducted in Africa, a continent with a high HIV prevalence (23) .
AIDS became the main cause of morbidity and mortality in the region due to the influence of the political, economic, and social crises these countries experienced in the 1980s together with the beginning of a global HIV epidemic focused on the historically most vulnerable racial groups. This scenario impacts, to this day, the poorest segments of the population, characterizing pauperization as one of the main social determinants of who falls ill and dies of AIDS (24) .
Regarding the factors associated with HIV in the adolescents and the youth, we found that the older the youth, the higher their risk of infection by the virus (16)(17)19,(21)(22) . However, early sexual initiation and absent condom use in their first sexual intercourse contributed to predisposing them to HIV, increasing infection vulnerability (16,21) .
Thus, we should mention that early sexual activity indicates the need for health promotion campaigns capable of increasing awareness about individual self-care to prevent HIV and strategies that reach adolescents and the youth not only to inform them but also to build knowledge and collaboration to collectively reduce HIV transmission (21) . We stress the importance of implementing these interventions in an accessible way and in environments capable of providing discussions on health promotion which value sexual and reproductive health (including the prevention of sexually transmitted infections/HIV) among adolescents and the youth even before their sexual initiation.
In total, two studies showed a higher risk of HIV diagnosis among young women (16,22) . Studies analyzing gender inequalities in HIV vulnerability in Africa also found this result, showing a feminization of seroprevalence due to aspects related to women's dependence and submission, difficulties in negotiating condom use, cultural and/or traditional practices, prostitution, and the male refusal to take tests and/or disclose their serological status to partners (25)(26)(27) in this population group (17,19,21) .
Moreover, HIV infection was higher among female groups who perceived themselves outside the infection risk (20) , an aggravating factor of the epidemic which requires actions aimed at reducing behaviors which make people vulnerable to infection. Thus, we stress that the approach of health education actions should align itself with the cultural issues of the African continent and turn to themes such as the consistent use of condoms, reduction of alcohol consumption, and the empowerment of women to negotiate safe sex with their partners (17,19) .
We note that African women also show a higher use of health services than men due to gestational, post-gestational, and family planning follow-ups, which leads to a higher testing for STIs/HIV in this population (23) .
On the other hand, African testing and counseling services face difficulties to perform HIV serological tests among its young male population (28) due to, in many cases, cross-cutting issues related to psychosocial, economic, and cultural aspects, such as machismo, perceptions of illness, work, and difficult access to health services (29) .
Research must also understand adolescents/the youth's relationships with their partners since we found a higher HIV risk among sexual relations with multiple people, partners who have other partners, and who have slept away from their homes for three or more nights (16,(19)(20) . It is important to address relationships during health promotion and prevention activities and, whenever possible, guide both partners to testing services, even if having a partner five years older is a protective factor against HIV infections (19) .
Studies must consider other aspects increasing HIV predisposition since we found a higher risk of living with the virus among people who consumed more alcohol (18)(19)(20) , practiced transactional sex, maintained sexual relations with partners living with HIV (20) , were widowed or divorced, and lived in separate homes (16,18) .
We observed such situations especially among women who suffer from scarce resources after the death of their partner or divorce and find a source of income in prostitution. Moreover, studies indicate that divorced the youth tend to consume large amounts of alcohol and have sex without the use of condoms, increasing their vulnerability to HIV (30)(31)(32) . intercourse on weekends (17) , variables which the assessed study should have better elucidated.
Although all chosen studies were conducted in Africa, a continent with a larger number of Black people, studies comparing the ethnicity of the subjects showed that ethnicities other than Black and higher levels of education were a protective factor for HIV (19,(21)(22) .
In this scenario, post-apartheid socio-historical relations show socially unprotected racial groups living with HIV/AIDS, guided by a residual model of social well-being with income transfer programs aimed at individuals in extreme poverty and inserted in basic social services to the detriment of intersectoral policies and technologies that guarantee access to education and health actions (25) .
This review also found a higher risk of HIV among people with a history of serological testing and STIs (17)(18)(20)(21) (16)(17)(18)(19) . Hence the importance of expanding the most vulnerable adolescents and the youth's access to condoms, including the use of female condoms since this is the population most affected by HIV in Africa.
Moreover, the risk of HIV decreases after circumcision (18) and